A Machine to Machine M2M communication network includes various M2M nodes and a bearer network. The M2M nodes implement mutual communication through the bearer network. One M2M node at least includes an Application Entity AE or a Common Service Entity CSE.
An M2M system architecture is as illustrated in FIG. 1. Herein, the application entity is a logic unit which actually executes an M2M application, while the common service entity is a logic unit which manages and serves the application.
In an M2M system architecture, an application node is an execution node at a terminal end, such as an intelligent electricity meter, a temperature measurement and control sensor, a fire alarm or an intelligent domestic electrical appliance and so on. An intermediate node is an intermediate which connects the execution node at the terminal end to a network-side server, such as a gateway. And a basic node is the network-side server, herein the application entity which is registered to the basic node usually is management software or a management platform of an M2M service provider.
Communication between M2M applications is implemented through interaction between CSEs. The communication is based on a premise that the M2M applications firstly need to be registered to local CSEs (e.g., an application entity at an application node in FIG. 1 needs to be registered to a CSE at an intermediate node, and the CSE at the intermediate node is a local CSE of the application entity at the application node), and then interaction between the M2M applications can be implemented through communication between CSEs.
The application node is a physical entity. The AE is a logic unit which actually executes an application at the physical entity, i.e., the application node.
When the AE is registered to the local CSE, the AE needs to provide a security certificate which can identify validity thereof to provide the security certificate to the local CSE for verification. The AE cannot be registered to the local CSE unless the verification passes. At the same time, the AE further needs to provide a registration name recommended by the AE to the local CSE for reference.
The registered AE may also create a resource related to the application at the local CSE, and the resource is used as a sub-resource of an application resource. For example, after the AE is registered, the local CSE will create a resource “application”, the application may also create a resource “container” under the resource “application” in order to save the data of the application, and the resource “container” is used for storing the data related to the AE. The AE may acquire a message indicating whether a certain resource changes by means of subscription. When an attribute or a sub-resource of the subscribed resource changes, e.g., a value of the attribute is modified, the sub-resource is deleted or a sub-resource is newly created or the like, the CSE at which the resource is located may send a notification message to the AE to notify the AE about that the concerned resource has already been modified.
The subscription of the resource is implemented by the AE creating a sub-resource with a type “subscription” under a resource to which the CSE expects to subscribe.
The resource to which the AE subscribed may include relatively many attributes and sub-resources, and thus a situation that these attributes and sub-resources are frequently modified may occur. However, according to the current subscription rule in the related art, a notification message will be sent to the AE at each time of modification, resulting in that the AE may frequently receive a great number of notification messages, which is not beneficial to the user experience and wastes the system resources.